Posterior Cruciate Ligament Injury

1. DR. ARSLAN LUQMAN
PGR ORTHOPEDICS
KHYBER TEACHING HOSPITAL

2. Posterior cruciate ligament (PCL) tears
comprise 3% of outpatient knee injuries and
38% of acute traumatic knee hemarthroses
These injuries rarely occur in isolation, and up
to 95% of PCL tears occur in combination with
other ligament injuries

3.  Anatomy of PCL
 Mechanism of Injury
 Clinical Evaluation
 Investigations
 Management

4.  Tibial footprint is located
between the posterior horns of
two menisci about 1–1.5 cm
below the posterior tibial
margin in the ‘PCL facet’

5.  AL and PL fibers further extend
upward and medially to be
attached onto the medial
femoral condyle.
 ALB is attached mostly to the
roof of the intercondylar notch
and PLB to the medial side of
the wall

6. More Important
in Extension of
the knee
More Important in
Flexion of the knee

7.  The PCL is also strengthened
by the meniscofemoral
ligaments (MFL), anteriorly
(ligament of Humphrey) and
posteriorly (ligament of
Wrisberg).

8.  Tensile loads are in the range of 2k to 3kN
 38 mm in length x 13 mm in diameter
 Diameter is 1.3 times larger than the ACL

9.  Posterior Tibial Translation
 Rotational and Medial/Lateral Stability
 Normal Joint contact pressure

10.  Restrains posterior tibial translation as the
knee moves from extension to flexion
throughout the arc of motion (0–120°)
especially from 30°–90° flexion
 Posteromedial, posterolateral capsule and
collaterals aid in the posterior restraint
between 0° and 30° flexion

11. Covey et al. demonstrated that Posterior
translation of tibia increases by two fold (7.23
± 0.65 mm) at 90° flexion as compared with
20° flexion (3.41 ± 0.77 mm) at 74 N
posteriorly directed force over tibia after
selective sectioning of the PCL

12.  The role the PCL plays in the rotational control of the knee
is still unclear, with many contradictory studies published
in the literature
 It restricts internal rotation at all flexion angles, PMB
particularly was reported to be controlling rotation beyond
90º of flexion
 It acts as a secondary stabilizer to rotational forces when
other ligaments are compromised and other ligaments may
provide control to rotation when the PCL is deficient

13.  The deficiency of the PCL results in increased
joint contact pressures in the medial and
patellofemoral compartments
 Untreated PCL deficiency have greater
incidence of medial and patellofemoral
compartment degeneration
Results showed significant posterior
subluxation of the tibia at 60° of flexion in the
PCL-deficient specimen, which resulted in
increased contact pressure and pressure
concentration in the medial compartment

14.  Direct blow to proximal tibia with a flexed knee
(dashboard injury)
 Hyperflexion with a plantar-flexed foot
 Hyperextension injury
 External rotation force on a weightbearing leg
with the knee in near full extension

15.  History
 Physical Examination

16.  Exploring the mechanism of injury
 Energy or velocity imparted to the knee
during the injury
 Did the knee swell up immediately?
 Could the patient bear weight? Did the knee
feel unstable?
 Current symptoms including pain, stiffness,
instability

17. Look
Feel
Move

18.  Posterior drawer test
 Posterior sag test (godfrey test)
 Quadriceps active test
 Dial test
 Varus/valgus stress

19.  Performed at 90º of knee flexion, and has a
sensitivity of 90% and a specificity of 99%
 Isolated PCL translate >10-12mm in neutral
and >6-8mm in internal rotation.
 Combined ligamentous injuries translate
> 15mm in neutral and >10mm in internal
rotation.

20.  Plane Radiography
 Stress Radiography
 Magnetic Resonance Imaging

21. A standard knee series, including
 bilateral standing (AP),
 AP flexion 45° weight bearing
 Lateral and
 Merchant patellar radiographs
should be evaluated for any evidence of avulsion
fractures, tibial subluxation and associated knee
injuries and chronic cartilage damage

22.  Stress radiography has been gaining
popularity for the diagnosis of multi-
ligamentous knee injuries
 It involves the application of a standardized
force to the knee to produce abnormal joint
displacement

23.  Several techniques have been described
including hamstring contraction, gravity
assisted, the Telos device and single-leg
kneeling
 The Telos device and kneeling have been
shown to be superior to other methods for
reproducibly demonstrating posterior knee
instability

24. A diagnostic algorithm has been validated where
side to side posterior translation difference has
been quantified
1. 0–7 mm = a partial PCL tear
2. 8–11 mm = isolated complete PCL tear
3. ≥12 mm = combined PCL and posterolateral
corner or posteromedial corner knee injury

25.  High sensitivity (near 100%) and specificity (near
97%)
 MRI is the radiologic study of choice in
diagnosing acute PCL tears, Although chronic
PCL injuries may be apparent on MRI it is not as
sensitive in diagnosing chronic tears
 MRI may appear normal as soon as 3 months
following low-to moderate-grade PCL injuries

26.  Normal PCL is homogeneously low signal on both
T2 and proton density weighted sequences,
lacking internal striations like ACL.
 Normal PCL should measure 6 mm or less, when
measured from anterior to posterior in the
sagittal plane

29. There are two potential pitfalls if one relies
only on the sagittal plane
 First, partial tears may be interpreted as
complete tears.
 Second, mucoid degeneration may mimic a
PCL tear in the setting of a functionally
stable ligament

30.  Nonoperative vs operative
 Repair vs reconstruction
 Autograft vs allograft
 Single vs double bundle
 Arthroscopic vs Open technique
 Rehabilitation

31.  Acute Isolated grade I and Grade II tears
(posterior tibal translation < 10mm)
 Asymptomatic patients
 Knee should be immobilized for 2-4weeks
 Functional dynamic force braces have been
designed to keep the knee in anterior drawer to
avoid laxity during healing
 Strengthening of quadriceps and avoiding
hamstrings use

32.  Grade III injuries with >10 mm of posterior
tibial displacement
 Symptomatic complete tears
 PCL tears with other ligamentous injuries
(ACL, MCL, PLC)
 Acute bony avulsion injuries of the PCL
attachment
 Failure of conservative management

33. Long-term subjective evaluations of patients are very
comparable
At a mean of 17 years after non operative treatment,
Shelbourne et al. found a mean IKDC score of 73,
which compares to IKDC scores of 65 found by 2nd
study of operative treatment that had much less
follow-up times of 9–10 years

34.  Arthroscopic primary PCL repair with suture
augmentation can be performed in patients
with proximal soft tissue avulsion tears
 Ligament remnants that can be re
approximated to the femoral wall and have
sufficient tissue quality to withhold sutures
can be primarily repaired rest needs
reconstruction

35.  Autograft
 Allograft
 Synthetic grafts

36.  Bone–patellar tendon–bone (B-PT-B)
 Hamstring (semitendinosus and/or gracilis)
 Quadriceps tendon–patellar bone (QTB)

37.  No risk of transmission of an infectious
disease
 Faster incorporation with adjacent tissues
 No risk of immune-mediated tissue rejection

38.  Achilles tendon
 Double-stranded anterior and posterior tibial
tendons
 Peroneus longus tendons

39.  Eliminates donor-site morbidity
 Multiple ligament injuries in which multiple
grafts will be required

40. Meta-analysis shows that the clinical
outcomes were similar between allograft
and autograft tendons for PCL
reconstruction

41.  Theoretically has the advantages of availability,
consistency, and appropriate mechanical strength,
no donor site morbidity and no risk of disease
transmission
 Eg. Carbon fiber, dacron, bundled
polytetrafluoroethylene (GORE-TEX™), ABC carbon,
polyester
 Longer term follow-up demonstrated recurrent
instability and chronic effusions hence their use is
controversial

42.  Only AL bundle is reconstructed during
single-bundle PCL reconstruction
 One femoral tunnel is made
 Both auto and allografts can be used

43.  Both ALB and PMB are reconstructed in
Double bundle PCLR
 Theoretically it restore the normal
kinematics
 It requires two separate femoral tunnels to
reconstruct ALB and PMB that puts femur at
risk for MFC fractures.

44. This systematic review found that double-
bundle reconstruction was superior to
single-bundle in biomechanical studies BUT
clinical outcomes showed no significant
differences between the two PCL
reconstruction techniques
Preferred technique is a single AL
bundle reconstruction because it
reduces surgery time and clinical
evidence demonstrates no advantage

45.  Transtibial tunnel technique
 Tibial-inlay technique

46.  Aims to simulate the tibial and femoral ALB
origins
 Incase of DB PCLR a 5-mm bone bridge is
maintained between femoral tunnels

47.  The main concern in this technique is the so-
called ‘killer turn’, the sharp angle on the tibial
tunnel exit that may produce abrasion,
attenuation and subsequent graft failure

48.  Proximity of neurovascular structures to the PCL
insertion is another challenge. The anterior wall
of the popliteal artery lies approximately 7–10
mm from the posterior border of the PCL at 90°
of flexion

53.  If only ALB is reconstructed the graft is
tensioned between 70°-90° of knee flexion
 For Double bundle PMB is tensioned is full
knee extension

54.  The two strongest advantages of tibial inlay
technique are its secure bone-to-bone
fixation on the tibia, and the elimination of
the “killer turn”
 Both open and arthroscopic techniques are in
practice

55.  Phase I ( 0 – 6 weeks)
 Phase II (6weeks – 6 months)
 Phase III (6 Months – 12 Months)

56.  1st 4 weeks= brace locked in full extension, passive
ROM up to 90° flexion, NWB with crutches
 After 4 weeks= brace unlocked to 100°, passive ROM
beyond 90°,weight bearing as tolerated with crutches
and brace on
 Quad sets ,Straight leg raise (SLR) with brace locked,
Ankle DF and PF, avoid active contraction of hamstrings
 Patella mobilization
 Discontinue brace and crutches at 6 weeks

57.  Passive stretching
 Closed chain exercises as tolerated
 Maximum knee flexion: 10–15° terminal
flexion deficit is not unusual
 Quadriceps strength 80–90 % of the
contralateral limb

58.  Quadriceps symmetry
 Open and closed chain exercises as tolerated
 Return to sport-specific activity as tolerated

59. They found the overall complication
rate for arthroscopic knee surgery was
4.7 %; however, 20.1 % of PCL
reconstructions had a complication

60.  Neurovascular injury
 Loss of flexion ( 10-20 degrees)
 Failure to obtain objective stability
 Osteonecrosis of the medial femoral condyle